Recent developments and experience in aerospace/engineering applications has established a clear superiority of layered composite zirconia/steel couples as ultra low wear. This has a great potential for implant applications in virtually eliminating wear particle mediated osteolysis and consequent implant failures. Wear rates comparable to ceramic/ceramic couples with demonstrated 2-3 orders lower wear volume than the best ceramic/PE couples can be expected. In contrast to the ceramic/ceramic couples however, the proposed composite ceramic/metal couple alleviates the major clinical concern stemming from brittle fracture. In a novel alternative approach to eliminating PE wear debris and lowering risk of brittle failure, a composite ceramic tibial component articulating against a Co-Cr femoral component is proposed. Developments and experience from the engineering fields is proposed to be applied to biomedical implant applications and is expected to lead to both superior wear resistance (comparable to the best ceramic/ceramic couples), with elimination of the PE tibial component. Toughness, enhancement of 2x over conventional ceramics significantly reduces risk of tibial failure. This is particularly relevant to mobile wearing knee designs where increased range of motion and resultant wear is observed. Phase 1 will establish the superior materials properties and demonstrate significantly reduced wear rates. In Phase 2, wear simulator tests will be conducted along with design and manufacturing process optimization. PROPOSED COMMERCIAL APPLICATION The novel combination of an ultra-tough composite ceramic tibial components articulating against Co-Cr femoral components will lead to negligible wear debris and implant failures. Adaptation and enhancement of an established engineering ceramic for articulation with the established Co-Cr condylar components will greatly enhance commercial applications.